Slaked lime, Ca(OH)2 is used extensively in sewage treatment. What is the maximum pH that can be established in Ca(OH)2(aq) ? Ca(OH)2(s)Ca2+(aq)+2OH-(aq); Ksp=5.5× 10-6

Question

Slaked lime, Ca(OH)2 is used extensively in sewage treatment. What is the maximum pH that can be established in Ca(OH)2(aq) ? Ca(OH)2(s)Ca2+(aq)+2OH-(aq); Ksp=5.5× 10-6  (A) 1.66 (B) 12.35 (C) 7 (D) 14

Tardigrade Admin · Accepted Answer

Ksp=5.5× 10-6 Ca(OH)2Ca2++2OH- ∴ Ksp=[Ca2+][OH-]2=5.5× 10-6 ⇒ 4s3=5.5× 10-6 ⇒ s=0.0111 ∴ [OH-]=2s=0.0111× 2=0.0222 pOH=1.65 pH=14-1.65=12.35

Q. Slaked lime, $C a (O H)_{2}$ is used extensively in sewage treatment. What is the maximum pH that can be established in $C a (O H)_{2} (a q)$ ? $C a (O H)_{2} (s) C a^{2 +} (a q) + 2 O H^{-} (a q);$ $K_{s p} = 5.5 \times 10^{- 6}$

1.66

12.35

7

14

$K_{s p} = 5.5 \times 10^{- 6}$ $C a (O H)_{2} C a^{2 +} + 2 O H^{-}$ $∴$ $K_{s p} = [C a^{2 +}] [O H^{-}]^{2} = 5.5 \times 10^{- 6}$ $\Rightarrow$ $4 s^{3} = 5.5 \times 10^{- 6}$ $\Rightarrow$ $s = 0.0111$ $∴$ $[O H^{-}] = 2 s = 0.0111 \times 2 = 0.0222$ $pO H = 1.65$ $p H = 14 - 1.65 = 12.35$

Q. Slaked lime, Ca(OH)2​ is used extensively in sewage treatment. What is the maximum pH that can be established in Ca(OH)2​(aq) ? Ca(OH)2​(s)Ca2+(aq)+2OH−(aq); Ksp​=5.5×10−6

1.66

12.35

7

14

Ksp​=5.5×10−6 Ca(OH)2​Ca2++2OH− ∴ Ksp​=[Ca2+][OH−]2=5.5×10−6 ⇒ 4s3=5.5×10−6 ⇒ s=0.0111 ∴ [OH−]=2s=0.0111×2=0.0222 pOH=1.65 pH=14−1.65=12.35

Q. Slaked lime, $C a (O H)_{2}$ is used extensively in sewage treatment. What is the maximum pH that can be established in $C a (O H)_{2} (a q)$ ? $C a (O H)_{2} (s) C a^{2 +} (a q) + 2 O H^{-} (a q);$ $K_{s p} = 5.5 \times 10^{- 6}$

$K_{s p} = 5.5 \times 10^{- 6}$ $C a (O H)_{2} C a^{2 +} + 2 O H^{-}$ $∴$ $K_{s p} = [C a^{2 +}] [O H^{-}]^{2} = 5.5 \times 10^{- 6}$ $\Rightarrow$ $4 s^{3} = 5.5 \times 10^{- 6}$ $\Rightarrow$ $s = 0.0111$ $∴$ $[O H^{-}] = 2 s = 0.0111 \times 2 = 0.0222$ $pO H = 1.65$ $p H = 14 - 1.65 = 12.35$